Lymphocyte homeostastis & regulation during aging

淋巴细胞稳态

• 批准号: 7264166
• 负责人: Michael Paul Cancro
• 金额: $ 38.28万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7264166
• 关键词: B lymphocyte; age difference; aging; autoantibody; bone marrow; cell differentiation; chimeric proteins; enhancer binding protein; gene induction /repression; gene rearrangement; genetically modified animals; growth factor receptors; helper T lymphocyte; homeostasis; immune response; immunogenetics; immunoglobulin genes; immunoglobulin isotypes; influenza; interleukin 1; laboratory mouse; microorganism hemagglutinin; nuclear factor kappa beta; protein reconstitution; transfection; tumor necrosis factor alpha

The size, composition, and dynamics of B cell subsets change with age, indicating shifts B cell homeostasis and selection. BLyS and its receptors play a central role in B cell homeostasis. Consequently, we hypothesize that BLyS mediated homeostatic processes are perturbed in aged individuals, leading to alterations in the dynamic and selective events that shape and maintain peripheral B cell pools. These studies will probe the relationship between BLyS-mediated homeostatic processes and age-associated changes among B cells. In aim 1, we will determine whether age-associated shifts in B cell subsets and repertoire selection rely on BLyS-BR3 mediated processes. Marrow and splenic.B lineage subsets of A/WySnJ and A/J mice at various ages will be characterized for representation, magnitude and turnover rate. In addition, repertoire diversity of immature, transitional, follicular, and MZ subsets will be assessed in A/J and A/WySnJ mice at various ages. These studies will employ limiting dilution and fine specificity analyses of the influenza hemagglutinin (HA)-specific response, as well as CDR3 length analyses. In aim 2, we will determine whether the lengthened lifespan of mature B cells in aged mice reflects enhanced ability to capture BLyS-BR3 signals. The levels of BLyS binding and BLyS receptor expression, as well as downstream mediators of BLyS and APRIL signaling, be followed as individuals age. We will establish whether these shifts reflect selection versus an intrinsic property of developing B cells in aged mice through analysis of reciprocal bone marrow chimeras. We will determine whether aged B cells enjoy a competitive advantage over young B cells in adoptive transfer, and whether this is abrogated by exogenous SLyS administration. In aim 3, we will determine whether the age-associated appearance of serum autoantibodies relies on BLyS mediated events. The experiments in this aim will also use the A/WsnJ and A/J strains for comparison. Age-associated appearance of ANAs will be followed, the B lineage subsets responsible for ANA antibody formation will be identified, and the repertoires of ANA producing clonotypes assessed. In addition, we will directly test whether transitional selection against autoreactive specificities changes with age through cloning and analysis of expressed VLVH pairs. In aims 1 -3, we will determine whether shifts in kinetics, selection and/or BLyS receptor expression in aged B cell populations reflect downstream outcomes of reduced EBP output, with Dr. Allman. In aim 4, we will determine whether manipulation of BLyS levels can restore robust B and T cell responses following immunization. We will examine the immune response to influenza HA in aged and young individuals to determine whether pretreatment with BLyS or BLyS receptor agonists restore litres of HA-specific antibody, as well as elevated HA-specific T cell, and B cell frequencies following immunization.

B细胞子集的大小，组成和动力学随着年龄的增长而变化，表明B细胞的变化 稳态和选择。 Blys及其受体在B细胞稳态中起着核心作用。 因此，我们假设Blys介导的稳态过程在老年中受到干扰 个体，导致动​​态和选择性事件的变化，这些事件形成和维持周边 B细胞池。这些研究将探究Blys介导的稳态过程之间的关系 B细胞之间与年龄相关的变化。在AIM 1中，我们将确定与年龄相关的 B细胞子集的变化和曲目选择取决于BLYS-BR3介导的过程。骨髓 A/Wysnj和A/J小鼠的splenic.b谱系子集将以各种年龄为特征 表示，大小和周转率。此外，曲目的多样性不成熟，过渡， 卵泡和MZ子集将在不同年龄的A/J和A/Wysnj小鼠中进行评估。这些研究会 采用局限性稀释和良好的特异性分析（HA）特异性反应， 以及CDR3长度分析。在AIM 2中，我们将确定延长的寿命是否 老年小鼠的成熟B细胞反映了捕获BLYS-BR3信号的增强能力。水平 Blys结合和Blys受体表达，以及Blys和Apror的下游介体 发出信号，随着个人的年龄而遵循。我们将确定这些转变是否反映了选择与 通过分析相互骨髓嵌合体的分析，在老年小鼠中发育的B细胞的内在特性。 我们将确定老年B细胞在收养中是否比年轻B细胞具有竞争优势 转移，以及是否被外在的slys施用消除。在AIM 3中，我们将确定 血清自身抗体的年龄相关外观是否依赖于Blys介导的事件。 此目标中的实验还将使用A/WSNJ和A/J菌株进行比较。与年龄相关 将遵循ANA的外观，负责ANA抗体形成的B谱系子集将 可以识别，并评估了ANA产生clonotypes的曲目。此外，我们将直接测试 针对自动反应特异性的过渡选择是否随着克隆和克隆而变化 分析表达的VLVH对。在目标1 -3中，我们将确定动力学的转移，选择 老年B细胞群体中的Blys受体表达反映了降低EBP的下游结果 输出，与Allman博士一起。在AIM 4中，我们将确定对BLYS级别的操纵是否可以恢复 免疫后强大的B和T细胞反应。我们将检查对 年龄和年轻人的流感HA确定是否对Blys或Blys进行预处理 受体激动剂恢复HA特异性抗体以及升高的HA特异性T细胞和B细胞的升 免疫后的频率。